ext/fiddle/closure.c (callback): static function

The `callback' function is not used outside of closure.c and
should not be able to cause namespace conflicts in compilers
without visibility pragmas.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@52198 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,7 @@
+Tue Oct 20 05:54:46 2015  Eric Wong  <e@80x24.org>
+
+	* ext/fiddle/closure.c (callback): static function
+
 Mon Oct 19 10:33:46 2015  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* ext/socket/init.c (rsock_raise_socket_error): get rid of a glibc

ext/fiddle/closure.c

@@ -55,7 +55,7 @@ const rb_data_type_t closure_data_type = {
     {0, dealloc, closure_memsize,},
 };
 
-void
+static void
 callback(ffi_cif *cif, void *resp, void **args, void *ctx)
 {
     VALUE self      = (VALUE)ctx;